IR3888A/B IR888A/B OptiMOS IPOL 20 A/16 A single-voltage synchronous Buck regulator Features Single 4.3 V to 17 V application or Wide Input Voltage Range from 2.0 V to 17 V with an External VCC Precision Reference Voltage (0.6 V +/- 0.5%) Enhanced Fast COT engine stable with Ceramic Output Capacitors and No External Compensation Forced Continuous Conduction Mode The Switching Frequency is set at 800 kHz internally Monotonic Start-Up with an internal Soft-Start Time & Enhanced Pre-Bias Start-Up Thermally Compensated Internal Over Current Protection Enable input with Voltage Monitoring Capability & Power Good Output Thermal Shut Down Operating Temp: -40 C < T < 125 C j Small Size: 6 mm x 5 mm PQFN Halogen-free and RoHS2 Compliant with Exemption 7a Potential applications Server Applications Storage Applications Telecom & Datacom Applications Distributed Point of Load Power Architectures Product validation Qualified for industrial applications according to the relevant tests of JEDEC47/20/22 Description The IR3888A/B is an easy-to-use, fully integrated dc - dc Buck regulator. The onboard PWM controller and OptiMOS FETs with integrated bootstrap diode make IR3888A/B a small footprint solution, providing high efficiency power delivery. Furthermore, it uses a fast Constant On-Time (COT) control scheme, which simplifies design efforts and achieves fast control response. The IR3888A/B has an internal low dropout voltage regulator, allowing operation with a single supply. It can also operate with an external bias supply, extending the operating input voltage (PVin) range. It features important protection functions, such as pre-bias start-up, thermally compensated current limits, over voltage and under voltage protection, and thermal shutdown to give required system level security in the event of fault conditions. Final Datasheet Please read the Important Notice and Warnings at the end of this document V2.2 www.infineon.com page 1 of 43 2021-7-20 IR888A/B OptiMOS IPOL 20 A/16 A single-voltage synchronous Buck regulator Table of contents Table of contents Features ........................................................................................................................................ 1 Potential applications ..................................................................................................................... 1 Product validation .......................................................................................................................... 1 Description .................................................................................................................................... 1 Table of contents ............................................................................................................................ 2 1 Ordering information ............................................................................................................. 4 2 Functional block diagram ........................................................................................................ 6 3 Typical application diagram .................................................................................................... 7 4 Pin descriptions ..................................................................................................................... 8 5 Absolute maximum ratings .................................................................................................... 10 6 Thermal Characteristics ......................................................................................................... 11 6.1 Thermal Characteristics ........................................................................................................................ 11 7 Electrical specifications ......................................................................................................... 12 7.1 Recommended operating conditions ................................................................................................... 12 7.2 Electrical characteristics ....................................................................................................................... 13 8 Typical efficiency and power loss curves .................................................................................. 15 8.1 PV = V = 12 V, F = 800 kHz ................................................................................................................ 15 in in sw 9 Thermal De-rating curves ....................................................................................................... 16 10 R of MOSFET Over Temperature ........................................................................................ 17 DS(ON) 11 Typical operating characteristics (-40 C T +125 C) .............................................................. 18 j 12 Theory of operation ............................................................................................................... 20 12.1 Fast Constant On-Time Control ............................................................................................................ 20 12.2 Enable .................................................................................................................................................... 20 12.3 FCCM Operation .................................................................................................................................... 21 12.4 Pseudo Constant Switching Frequency ................................................................................................ 21 12.5 Soft-start ................................................................................................................................................ 21 12.6 Pre-bias Start-up ................................................................................................................................... 22 12.7 Internal Low - Dropout (LDO) Regulator ............................................................................................... 22 12.8 Over Current Protection (OCP) ............................................................................................................. 22 12.9 Under Voltage Protection (UVP) ........................................................................................................... 23 12.10 Over Voltage Protection (OVP) .............................................................................................................. 24 12.11 Over Temperature Protection (OTP) .................................................................................................... 24 12.12 Power Good (PGood) Output ................................................................................................................ 24 12.13 Minimum On - Time and Minimum Off - Time ...................................................................................... 25 12.14 Selection of Feedforward Capacitor and Feedback Resistors ............................................................. 25 13 Design example ..................................................................................................................... 27 13.1 Enabling the IR3888A ............................................................................................................................ 27 13.2 Selecting Input Capacitors .................................................................................................................... 27 13.3 Inductor Selection ................................................................................................................................. 28 13.4 Output Capacitor Selection .................................................................................................................. 28 13.5 Output Voltage Programming............................................................................................................... 29 13.6 Feedforward Capacitor ......................................................................................................................... 29 13.7 Bootstrap Capacitor .............................................................................................................................. 29 13.8 VIN and VCC/LDO bypass Capacitor ..................................................................................................... 29 Final Datasheet 2 of 43 V2.2 2021-7-20